Members of the British public greatly overestimate the country’s Muslim population and think the number is growing at a far greater rate than it really is, a new “Index of Ignorance” study has found.

The Ipsos Mori survey, The Perils of Perception, measured the gap between public perception and reality in 40 countries in 2016 for a wide range of topics. It aims to highlight how wrong people are about key global and national issues.

For the UK, the results found respondents believed one in six civilians is Muslim, when the real proportion is less than one in 20.

The poll also showed that members of the public think 22 percent of Britain’s population will be Muslim by 2020, when researchers have put the figure closer to six percent.

It found French respondents were by far the most likely to overstate their country’s current and projected Muslim population. The average French estimate was that 31 percent of the population was Muslim, though it actually stands at 7.5 percent – or one in 13 people.

The survey also asked Britons to put a figure on the percentage of people in the country who considered themselves happy.

They found that Brits think their fellow countrymen are much more miserable than they really are. Respondents thought just 47 percent of Brits were happy, when in fact 92 percent said they were.

The British public also thought others were less accepting of homosexuality than they report in surveys. Britons thought 28 percent of the public would find homosexuality morally unacceptable, when 17 percent actually said that.

Respondents also thought more people are anti-abortion than they really are. Britons thought 34 percent of people found abortion morally unacceptable, when 25 percent say they do.